"Barcode Scanner+" (paid) is supposed to be able to read at least some PDF417 barcodes - the 2D ones that are showing up on more boarding passes. I've also occasionally been able to get ScanLife (free) to read smaller ones, but it has too small a window for the more rectangular ones.

This is also mentioned on the UA thread listed above as "Manatee." I'd recommend going into settings and making sure everything is checked, and that hi-res scans are enabled (unless you have a really old device). This app works better than any android barcode scanner app I've ever used, not just for BP's, but in general.